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Tool and Fixture Design for Ultrasonic Spot Welding of Dissimilar Metal Sheets
Published in Susanta Kumar Sahoo, Mantra Prasad Satpathy, Ultrasonic Welding of Metal Sheets, 2020
Susanta Kumar Sahoo, Mantra Prasad Satpathy
Likewise, Figure 3.28 demonstrates a comparison of joint strengths for serrated and trapezoidal sonotrode edges at various welding times. Here the bonded zone expands in the direction of welding with the increase in weld time. For the serrated-type sonotrode knurls, the plastic flow starts from the top specimen to the weld interface, and it results in growth of the bonded zone, which enhances the joint strength. However, the trapezoidal sonotrode edge shows less plastic deformation and a partially developed bonding zone. Thus, the joint strength is higher with a serrated edge than with a trapezoidal-type edge over the same welding time and weld pressure. Moreover, the normal stress imparted by the serrated sonotrode edge on the weld interface is higher than that generated by the trapezoidal edge, due to the serrated edge's low penetration capability and high contact area which yield the improvement in joint strength.
Hand and power tools
Published in Andrew Livesey, Alan Robinson, The Repair of Vehicle Bodies, 2018
Monodex cutters. This tool is designed for cutting thin sheet metal. Unlike snips, it has a flat face with one central serrated blade which in use cuts a slot equal in width to the thickness of the blade, 3 mm (1/8 inch). As the material is cut, it coils up in front of the cutters. The advantage of this tool is that it can cut sheet metal internally, and work along either a straight or curved line by drilling a small access hole in the metal to allow the blade to penetrate through the metal to commence cutting. Allowance must be made for the wastage of 3 mm strip (1/8 inch) when cutting to a final size.
Important Regions in Conventional Carding
Published in Ashok R. Khare, Principles of Spinning, 2022
The real success in the development of increasing card production was owing to the introduction of metallic wires. In the manufacturing process (Figure 2.35), a wire with a round section is flattened and rolled into a long strip comprising (a) a rib to constitute the base of the wire, and (b) a thin web forming a portion for teeth. This thin portion is stamped or punched so as to leave a thin serrated strip called saw tooth wire. It is also frequently called rigid wire—an apt designation. The tooth thus formed is very solid, strong and sturdy.
Aerodynamic performance enhancement and computational methods for H-Darrieus vertical axis wind turbines: Review
Published in International Journal of Green Energy, 2022
Temesgen Abriham Miliket, Mesfin Belayneh Ageze, Muluken Temesgen Tigabu
Leading-edge serration effectively reduces the boundary layer flow separation and is allowed to accelerate the flow from the pressure side to the suction side of the slot (Mohamed et al. 2020). It improves the power outputs of VAWTat low TSR (Lositaño and Danao 2018a; Wang and Zhuang 2017). It was applied in the H-Darrieus rotor with NACA0018 blade and the flow separation was reduced through the grooved section and the power coefficient was 18.3% higher than the baseline blade (unserrated NACA0018 blade) (Wang, Wang, and Zhuang 2018). However, this method was also implemented in a 5 KW H-Darrieus with NACA0025 airfoil blade against a massive vortex flow and leads to poor performance (Lositaño and Danao 2019). A serrated blade in a VAWT generates high turbulence instead of containing or decreasing it as was presumed (Lositaño and Danao 2018). Hence the concept of leading-edge serration is somehow a contradicted idea and needs more investigation.
Research on the evolution of serrated chips in high-speed cutting based on digital microscope
Published in Machining Science and Technology, 2020
Guohe Li, Yujun Cai, Houjun Qi, Meng Liu, Xiaole Qi
Figure 7 is the chip obtained from experiments. A short segment of approximately 2–3 mm is taken from the chip to observe. Figures 8 and 9 give a typical observation result of Ti6Al4V and AISI 1045, respectively. It shows that when the DM is adopted, the chip can be investigated directly, and a clear 2D or 3D results can be obtained. The pitch and height of saw-tooth are need to measure for the analysis of serrated chip. Firstly, the magnification 100× is used to observe the whole range of chip depth, and the top height of saw-tooth H is measured by the function of profile measurement, as shown in Figures 10a and 11a. Then the magnification 500× is used to observe the partial of saw-tooth, the H-h, namely the difference value between the tooth top height and tooth root height, and the segment spacing can be obtained, as shown in Figures 9b and 10b. According to Equation (2), the degree of segmentation Gs can be calculated.
Studies on chip morphology and modes of tool wear during machining of Ti-6Al-4V using uncoated carbide tool: application of multi-walled carbon nanotubes added rice bran oil as nanocutting fluid
Published in Machining Science and Technology, 2020
Thrinadh Jadam, Saurav Datta, Manoj Masanta
Optical micrographs exhibiting chip micro-morphology for dry and NFMQL with varied Vcs are furnished in Figure 23. Chip micro-morphology is composed of serrated toothed (also called saw-toothed) profile which can further be described by several quantitative parameters including tooth spacing (pitch/segmentation spacing) (Pc), shear angle (Ɵ), saw-tooth included angle (Ψ), maximum height of serrated toothed profile (H), minimum height of serrated toothed profile (h), etc. (Figure 24a,b). As indicated in Figure 24a, area above orange boarder is called undeformed area while below the orange boarder, there exists deformed area. Another distinguishable feature of chip’s micro-morphology is the formation of adiabatic shear band. Adiabatic shear band width (δ), shear band spacing (Lc) and grain orientation within shear band are shown in Figure 25.